Effort reply while I’m on my lunch break. I wrote this in response to @DefinitelyNotAPhone, but replying here so you see it as well since you asked.

How does someone even get like this?

Because the first act of violence the patriarchy forces men to preform is against themselves. Above all, being a man is defined in terms of things you aren't, as opposed to things you are.

Example: You aren't weak, you aren't effeminate, you aren't submissive, and so on. But people are those things in different ways and at different times, at least in broad strokes.

So the first thing men have to do in order to be patriarchal, which they've been told is synonymous with successful, is to be violent towards themselves, to destroy bits and pieces of themselves.

That violence spills over into all other aspects of patriarchal violence. If you've internalized hating femininity to validate your own sense of worth as a man, then it becomes very difficult to love women or even tolerate anyone / anything that isn't strictly defined as "masculine".

Through conditioning men to be violent towards themselves, the patriarchy normalizes violence in general.